NHTSA Complaint #11643702 — 2023 GMC ACADIA

I am experiencing a recurring P04FB diagnostic trouble code on my 2023 GMC Acadia, related to the crankcase pressure sensor. GM issued Bulletin No. PIP5841C, which attributes the issue to moisture buildup freezing inside the sensor. Their recommended fix is to remove the sensor, blow out any moisture, and reinstall it. However, this is not a permanent solution—the code returns within days, suggesting an inherent design flaw in the PCV system. Additionally, the replacement sensor (Part #12718935) is on national backorder, making it impossible to obtain. Many owners across multiple GM models using this engine (such as the Chevrolet Blazer and Cadillac XT4) are experiencing the same problem, yet GM has not provided a real solution. A properly designed PCV system should not allow excessive moisture to accumulate in the sensor. Instead of addressing the root cause, GM’s bulletin merely delays the issue by temporarily clearing the moisture. This approach does not prevent the problem from recurring, and it does not fix the underlying defect. If the sensor fails or provides inaccurate readings, it can affect emissions and engine performance. The fact that the replacement part is unavailable suggests GM may be restricting access to it, possibly because they know it is defective. This raises concerns that GM is quietly managing a widespread issue rather than issuing a formal recall or warranty extension. I am requesting that the NHTSA investigate this issue, as GM's current approach does not resolve the problem. Owners should not be forced to repeatedly clear moisture from a sensor that is failing due to a design flaw. If GM has internally identified a better solution, it should be made available to affected owners instead of delaying action with ineffective temporary fixes.